trunk/src/files.c

/***************************************
 $Header: /home/amb/CVS/routino/src/files.c,v 1.25 2010-10-31 17:52:40 amb Exp $

 Functions to handle files.

 Part of the Routino routing software.
 ******************/ /******************
 This file Copyright 2008-2010 Andrew M. Bishop

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Affero General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Affero General Public License for more details.

 You should have received a copy of the GNU Affero General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ***************************************/

#include <assert.h>

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/types.h>

#include "files.h"


/*+ A structure to contain the list of memory mapped files. +*/
struct mmapinfo
{
 const char  *filename;         /*+ The name of the file (the index of the list). +*/
       int    fd;               /*+ The file descriptor used when it was opened. +*/
       void  *address;          /*+ The address the file was mapped to. +*/
       size_t length;           /*+ The length of the file. +*/
};

/*+ The list of memory mapped files. +*/
static struct mmapinfo *mappedfiles;

/*+ The number of mapped files. +*/
static int nmappedfiles=0;


/*++++++++++++++++++++++++++++++++++++++
  Return a filename composed of the dirname, prefix and filename.

  char *FileName Returns an allocated filename.

  const char *dirname The directory name.

  const char *prefix The file prefix.

  const char *name The filename.
  ++++++++++++++++++++++++++++++++++++++*/

char *FileName(const char *dirname,const char *prefix, const char *name)
{
 char *filename=(char*)malloc((dirname?strlen(dirname):0)+1+(prefix?strlen(prefix):0)+1+strlen(name)+1);

 sprintf(filename,"%s%s%s%s%s",dirname?dirname:"",dirname?"/":"",prefix?prefix:"",prefix?"-":"",name);

 return(filename);
}


/*++++++++++++++++++++++++++++++++++++++
  Open a file and map it into memory.

  void *MapFile Returns the address of the file or exits in case of an error.

  const char *filename The name of the file to open.
  ++++++++++++++++++++++++++++++++++++++*/

void *MapFile(const char *filename)
{
 int fd;
 off_t size;
 void *address;

 /* Open the file and get its size */

 fd=ReOpenFile(filename);

 size=SizeFile(filename);

 /* Map the file */

 address=mmap(NULL,size,PROT_READ,MAP_SHARED,fd,0);

 if(address==MAP_FAILED)
   {
    close(fd);

    assert(0);

    fprintf(stderr,"Cannot mmap file '%s' for reading [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 mappedfiles=(struct mmapinfo*)realloc((void*)mappedfiles,(nmappedfiles+1)*sizeof(struct mmapinfo));

 mappedfiles[nmappedfiles].filename=filename;
 mappedfiles[nmappedfiles].fd=fd;
 mappedfiles[nmappedfiles].address=address;
 mappedfiles[nmappedfiles].length=size;

 nmappedfiles++;

 return(address);
}


/*++++++++++++++++++++++++++++++++++++++
  Open a file and map it into memory.

  void *MapFileWriteable Returns the address of the file or exits in case of an error.

  const char *filename The name of the file to open.
  ++++++++++++++++++++++++++++++++++++++*/

void *MapFileWriteable(const char *filename)
{
 int fd;
 off_t size;
 void *address;

 /* Open the file and get its size */

 fd=ReOpenFileWriteable(filename);

 size=SizeFile(filename);

 /* Map the file */

 address=mmap(NULL,size,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);

 if(address==MAP_FAILED)
   {
    close(fd);

    fprintf(stderr,"Cannot mmap file '%s' for reading and writing [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 mappedfiles=(struct mmapinfo*)realloc((void*)mappedfiles,(nmappedfiles+1)*sizeof(struct mmapinfo));

 mappedfiles[nmappedfiles].filename=filename;
 mappedfiles[nmappedfiles].fd=fd;
 mappedfiles[nmappedfiles].address=address;
 mappedfiles[nmappedfiles].length=size;

 nmappedfiles++;

 return(address);
}


/*++++++++++++++++++++++++++++++++++++++
  Unmap a file.

  void *UnmapFile Returns NULL (for similarity to the MapFile function).

  const char *filename The name of the file when it was opened.
  ++++++++++++++++++++++++++++++++++++++*/

void *UnmapFile(const char *filename)
{
 int i;

 for(i=0;i<nmappedfiles;i++)
    if(!strcmp(mappedfiles[i].filename,filename))
       break;

 if(i==nmappedfiles)
   {
    fprintf(stderr,"The file '%s' was not mapped using MapFile().\n",filename);
    exit(EXIT_FAILURE);
   }

 /* Close the file */

 close(mappedfiles[i].fd);

 /* Unmap the file */

 munmap(mappedfiles[i].address,mappedfiles[i].length);

 /* Shuffle the list of files */

 nmappedfiles--;

 if(nmappedfiles>i)
    memmove(&mappedfiles[i],&mappedfiles[i+1],(nmappedfiles-i)*sizeof(struct mmapinfo));

 return(NULL);
}


/*++++++++++++++++++++++++++++++++++++++
  Open a new file on disk for writing to.

  int OpenFileNew Returns the file descriptor if OK or exits in case of an error.

  const char *filename The name of the file to create.
  ++++++++++++++++++++++++++++++++++++++*/

int OpenFileNew(const char *filename)
{
 int fd;

 /* Open the file */

 fd=open(filename,O_RDWR|O_CREAT|O_TRUNC,S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);

 if(fd<0)
   {
    fprintf(stderr,"Cannot open file '%s' for writing [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 return(fd);
}


/*++++++++++++++++++++++++++++++++++++++
  Open a new file on disk for reading from and appending.

  int OpenFileAppend Returns the file descriptor if OK or exits in case of an error.

  const char *filename The name of the file to create.
  ++++++++++++++++++++++++++++++++++++++*/

int OpenFileAppend(const char *filename)
{
 int fd;

 /* Open the file */

 fd=open(filename,O_RDWR|O_CREAT|O_APPEND,S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);

 if(fd<0)
   {
    fprintf(stderr,"Cannot open file '%s' for appending [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 return(fd);
}


/*++++++++++++++++++++++++++++++++++++++
  Open an existing file on disk for reading.

  int ReOpenFile Returns the file descriptor if OK or exits in case of an error.

  const char *filename The name of the file to open.
  ++++++++++++++++++++++++++++++++++++++*/

int ReOpenFile(const char *filename)
{
 int fd;

 /* Open the file */

 fd=open(filename,O_RDONLY);

 if(fd<0)
   {
    fprintf(stderr,"Cannot open file '%s' for reading [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 return(fd);
}


/*++++++++++++++++++++++++++++++++++++++
  Open an existing file on disk for reading from or writing to.

  int ReOpenFileWriteable Returns the file descriptor if OK or exits in case of an error.

  const char *filename The name of the file to open.
  ++++++++++++++++++++++++++++++++++++++*/

int ReOpenFileWriteable(const char *filename)
{
 int fd;

 /* Open the file */

 fd=open(filename,O_RDWR);

 if(fd<0)
   {
    fprintf(stderr,"Cannot open file '%s' for reading and writing [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 return(fd);
}


/*++++++++++++++++++++++++++++++++++++++
  Get the size of a file.

  off_t SizeFile Returns the file size.

  const char *filename The name of the file to check.
  ++++++++++++++++++++++++++++++++++++++*/

off_t SizeFile(const char *filename)
{
 struct stat buf;

 if(stat(filename,&buf))
   {
    fprintf(stderr,"Cannot stat file '%s' [%s].\n",filename,strerror(errno));
    exit(EXIT_FAILURE);
   }

 return(buf.st_size);
}


/*++++++++++++++++++++++++++++++++++++++
  Check if a file exists.

  int ExistsFile Returns 1 if the file exists and 0 if not.

  const char *filename The name of the file to check.
  ++++++++++++++++++++++++++++++++++++++*/

int ExistsFile(const char *filename)
{
 struct stat buf;

 if(stat(filename,&buf))
    return(0);
 else
    return(1);
}


/*++++++++++++++++++++++++++++++++++++++
  Close a file on disk.

  int fd The file descriptor to close.
  ++++++++++++++++++++++++++++++++++++++*/

void CloseFile(int fd)
{
 close(fd);
}


/*++++++++++++++++++++++++++++++++++++++
  Delete a file from disk.

  int DeleteFile Returns 0 if OK or something else in case of an error.

  char *filename The name of the file to delete.
  ++++++++++++++++++++++++++++++++++++++*/

int DeleteFile(char *filename)
{
 unlink(filename);

 return(0);
}
1	amb	2	/***************************************
2	amb	518	$Header: /home/amb/CVS/routino/src/files.c,v 1.25 2010-10-31 17:52:40 amb Exp $
3	amb	2
4	amb	326	Functions to handle files.
5	amb	151
6			Part of the Routino routing software.
7	amb	2	****************/ /****************
8	amb	326	This file Copyright 2008-2010 Andrew M. Bishop
9	amb	2
10	amb	151	This program is free software: you can redistribute it and/or modify
11			it under the terms of the GNU Affero General Public License as published by
12			the Free Software Foundation, either version 3 of the License, or
13			(at your option) any later version.
14
15			This program is distributed in the hope that it will be useful,
16			but WITHOUT ANY WARRANTY; without even the implied warranty of
17			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18			GNU Affero General Public License for more details.
19
20			You should have received a copy of the GNU Affero General Public License
21			along with this program. If not, see <http://www.gnu.org/licenses/>.
22	amb	2	***************************************/
23
24	amb	507	#include <assert.h>
25	amb	2
26			#include <unistd.h>
27			#include <stdlib.h>
28	amb	449	#include <stdio.h>
29	amb	162	#include <string.h>
30	amb	2	#include <fcntl.h>
31	amb	330	#include <errno.h>
32	amb	2	#include <sys/stat.h>
33			#include <sys/mman.h>
34	amb	251	#include <sys/types.h>
35	amb	2
36	amb	449	#include "files.h"
37	amb	2
38
39	amb	289	/+ A structure to contain the list of memory mapped files. +/
40	amb	248	struct mmapinfo
41			{
42	amb	289	const char filename; /+ The name of the file (the index of the list). +*/
43			int fd; /+ The file descriptor used when it was opened. +/
44			void address; /+ The address the file was mapped to. +*/
45			size_t length; /+ The length of the file. +/
46	amb	248	};
47
48	amb	289	/+ The list of memory mapped files. +/
49			static struct mmapinfo *mappedfiles;
50	amb	248
51	amb	289	/+ The number of mapped files. +/
52			static int nmappedfiles=0;
53	amb	248
54	amb	289
55	amb	2	/*++++++++++++++++++++++++++++++++++++++
56	amb	162	Return a filename composed of the dirname, prefix and filename.
57
58			char *FileName Returns an allocated filename.
59
60			const char *dirname The directory name.
61
62			const char *prefix The file prefix.
63
64			const char *name The filename.
65			++++++++++++++++++++++++++++++++++++++*/
66
67			char FileName(const char dirname,const char prefix, const char name)
68			{
69	amb	518	char filename=(char)malloc((dirname?strlen(dirname):0)+1+(prefix?strlen(prefix):0)+1+strlen(name)+1);
70	amb	162
71			sprintf(filename,"%s%s%s%s%s",dirname?dirname:"",dirname?"/":"",prefix?prefix:"",prefix?"-":"",name);
72
73			return(filename);
74			}
75
76
77			/*++++++++++++++++++++++++++++++++++++++
78	amb	250	Open a file and map it into memory.
79	amb	2
80	amb	331	void *MapFile Returns the address of the file or exits in case of an error.
81	amb	2
82			const char *filename The name of the file to open.
83			++++++++++++++++++++++++++++++++++++++*/
84
85	amb	250	void MapFile(const char filename)
86	amb	2	{
87			int fd;
88	amb	331	off_t size;
89	amb	2	void *address;
90
91	amb	331	/* Open the file and get its size */
92	amb	2
93	amb	331	fd=ReOpenFile(filename);
94	amb	2
95	amb	331	size=SizeFile(filename);
96	amb	2
97			/* Map the file */
98
99	amb	331	address=mmap(NULL,size,PROT_READ,MAP_SHARED,fd,0);
100	amb	2
101	amb	245	if(address==MAP_FAILED)
102	amb	2	{
103			close(fd);
104	amb	177
105	amb	507	assert(0);
106
107	amb	511	fprintf(stderr,"Cannot mmap file '%s' for reading [%s].\n",filename,strerror(errno));
108	amb	177	exit(EXIT_FAILURE);
109	amb	2	}
110
111	amb	248	mappedfiles=(struct mmapinfo)realloc((void)mappedfiles,(nmappedfiles+1)*sizeof(struct mmapinfo));
112
113			mappedfiles[nmappedfiles].filename=filename;
114			mappedfiles[nmappedfiles].fd=fd;
115			mappedfiles[nmappedfiles].address=address;
116	amb	331	mappedfiles[nmappedfiles].length=size;
117	amb	248
118			nmappedfiles++;
119
120	amb	2	return(address);
121			}
122
123
124			/*++++++++++++++++++++++++++++++++++++++
125	amb	507	Open a file and map it into memory.
126
127	amb	513	void *MapFileWriteable Returns the address of the file or exits in case of an error.
128	amb	507
129			const char *filename The name of the file to open.
130			++++++++++++++++++++++++++++++++++++++*/
131
132			void MapFileWriteable(const char filename)
133			{
134			int fd;
135			off_t size;
136			void *address;
137
138			/* Open the file and get its size */
139
140	amb	511	fd=ReOpenFileWriteable(filename);
141	amb	507
142			size=SizeFile(filename);
143
144			/* Map the file */
145
146			address=mmap(NULL,size,PROT_READ\|PROT_WRITE,MAP_SHARED,fd,0);
147
148			if(address==MAP_FAILED)
149			{
150			close(fd);
151
152	amb	511	fprintf(stderr,"Cannot mmap file '%s' for reading and writing [%s].\n",filename,strerror(errno));
153	amb	507	exit(EXIT_FAILURE);
154			}
155
156			mappedfiles=(struct mmapinfo)realloc((void)mappedfiles,(nmappedfiles+1)*sizeof(struct mmapinfo));
157
158			mappedfiles[nmappedfiles].filename=filename;
159			mappedfiles[nmappedfiles].fd=fd;
160			mappedfiles[nmappedfiles].address=address;
161			mappedfiles[nmappedfiles].length=size;
162
163			nmappedfiles++;
164
165			return(address);
166			}
167
168
169			/*++++++++++++++++++++++++++++++++++++++
170	amb	331	Unmap a file.
171	amb	2
172	amb	289	void *UnmapFile Returns NULL (for similarity to the MapFile function).
173	amb	255
174	amb	248	const char *filename The name of the file when it was opened.
175			++++++++++++++++++++++++++++++++++++++*/
176
177	amb	255	void UnmapFile(const char filename)
178	amb	248	{
179			int i;
180
181			for(i=0;i<nmappedfiles;i++)
182			if(!strcmp(mappedfiles[i].filename,filename))
183			break;
184
185			if(i==nmappedfiles)
186			{
187	amb	330	fprintf(stderr,"The file '%s' was not mapped using MapFile().\n",filename);
188	amb	248	exit(EXIT_FAILURE);
189			}
190
191			/* Close the file */
192
193			close(mappedfiles[i].fd);
194
195			/* Unmap the file */
196
197			munmap(mappedfiles[i].address,mappedfiles[i].length);
198
199			/* Shuffle the list of files */
200
201			nmappedfiles--;
202
203			if(nmappedfiles>i)
204			memmove(&mappedfiles[i],&mappedfiles[i+1],(nmappedfiles-i)*sizeof(struct mmapinfo));
205	amb	255
206			return(NULL);
207	amb	248	}
208
209
210			/*++++++++++++++++++++++++++++++++++++++
211			Open a new file on disk for writing to.
212
213	amb	513	int OpenFileNew Returns the file descriptor if OK or exits in case of an error.
214	amb	248
215	amb	97	const char *filename The name of the file to create.
216	amb	2	++++++++++++++++++++++++++++++++++++++*/
217
218	amb	502	int OpenFileNew(const char *filename)
219	amb	2	{
220	amb	97	int fd;
221	amb	2
222	amb	97	/* Open the file */
223	amb	2
224	amb	448	fd=open(filename,O_RDWR\|O_CREAT\|O_TRUNC,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
225	amb	2
226	amb	97	if(fd<0)
227	amb	177	{
228	amb	330	fprintf(stderr,"Cannot open file '%s' for writing [%s].\n",filename,strerror(errno));
229	amb	177	exit(EXIT_FAILURE);
230			}
231	amb	2
232	amb	97	return(fd);
233	amb	2	}
234
235
236			/*++++++++++++++++++++++++++++++++++++++
237	amb	502	Open a new file on disk for reading from and appending.
238	amb	326
239	amb	502	int OpenFileAppend Returns the file descriptor if OK or exits in case of an error.
240	amb	326
241			const char *filename The name of the file to create.
242			++++++++++++++++++++++++++++++++++++++*/
243
244	amb	502	int OpenFileAppend(const char *filename)
245	amb	326	{
246			int fd;
247
248			/* Open the file */
249
250			fd=open(filename,O_RDWR\|O_CREAT\|O_APPEND,S_IRUSR\|S_IWUSR\|S_IRGRP\|S_IROTH);
251
252			if(fd<0)
253			{
254	amb	330	fprintf(stderr,"Cannot open file '%s' for appending [%s].\n",filename,strerror(errno));
255	amb	326	exit(EXIT_FAILURE);
256			}
257
258			return(fd);
259			}
260
261
262			/*++++++++++++++++++++++++++++++++++++++
263	amb	511	Open an existing file on disk for reading.
264	amb	251
265	amb	331	int ReOpenFile Returns the file descriptor if OK or exits in case of an error.
266	amb	251
267			const char *filename The name of the file to open.
268			++++++++++++++++++++++++++++++++++++++*/
269
270			int ReOpenFile(const char *filename)
271			{
272			int fd;
273
274			/* Open the file */
275
276	amb	511	fd=open(filename,O_RDONLY);
277	amb	251
278			if(fd<0)
279			{
280	amb	330	fprintf(stderr,"Cannot open file '%s' for reading [%s].\n",filename,strerror(errno));
281	amb	251	exit(EXIT_FAILURE);
282			}
283
284			return(fd);
285			}
286
287
288			/*++++++++++++++++++++++++++++++++++++++
289	amb	511	Open an existing file on disk for reading from or writing to.
290
291			int ReOpenFileWriteable Returns the file descriptor if OK or exits in case of an error.
292
293			const char *filename The name of the file to open.
294			++++++++++++++++++++++++++++++++++++++*/
295
296			int ReOpenFileWriteable(const char *filename)
297			{
298			int fd;
299
300			/* Open the file */
301
302			fd=open(filename,O_RDWR);
303
304			if(fd<0)
305			{
306			fprintf(stderr,"Cannot open file '%s' for reading and writing [%s].\n",filename,strerror(errno));
307			exit(EXIT_FAILURE);
308			}
309
310			return(fd);
311			}
312
313
314			/*++++++++++++++++++++++++++++++++++++++
315	amb	331	Get the size of a file.
316
317			off_t SizeFile Returns the file size.
318
319			const char *filename The name of the file to check.
320			++++++++++++++++++++++++++++++++++++++*/
321
322			off_t SizeFile(const char *filename)
323			{
324			struct stat buf;
325
326			if(stat(filename,&buf))
327			{
328			fprintf(stderr,"Cannot stat file '%s' [%s].\n",filename,strerror(errno));
329			exit(EXIT_FAILURE);
330			}
331
332			return(buf.st_size);
333			}
334
335
336			/*++++++++++++++++++++++++++++++++++++++
337	amb	341	Check if a file exists.
338
339			int ExistsFile Returns 1 if the file exists and 0 if not.
340
341			const char *filename The name of the file to check.
342			++++++++++++++++++++++++++++++++++++++*/
343
344			int ExistsFile(const char *filename)
345			{
346			struct stat buf;
347
348			if(stat(filename,&buf))
349			return(0);
350			else
351			return(1);
352			}
353
354
355			/*++++++++++++++++++++++++++++++++++++++
356	amb	97	Close a file on disk.
357	amb	87
358	amb	97	int fd The file descriptor to close.
359	amb	87	++++++++++++++++++++++++++++++++++++++*/
360
361	amb	97	void CloseFile(int fd)
362	amb	87	{
363	amb	97	close(fd);
364	amb	87	}
365	amb	251
366
367			/*++++++++++++++++++++++++++++++++++++++
368			Delete a file from disk.
369
370			int DeleteFile Returns 0 if OK or something else in case of an error.
371
372			char *filename The name of the file to delete.
373			++++++++++++++++++++++++++++++++++++++*/
374
375			int DeleteFile(char *filename)
376			{
377			unlink(filename);
378
379			return(0);
380			}